"Terrorists detonate car bomb between Sabaa Bahrat square and Shahbander Street," the television reported, adding that initial information suggested that the explosion was a suicide attack.

"The preliminary toll from the terrorist bombing... is more than 15 martyrs and 53 injuries," the broadcaster added.

A news correspondent said the blast caused extensive damage and that intense gunfire could be heard shortly afterwards.

State television broadcast scenes of devastation, with huge plumes of thick black smoke billowing up around buildings in the area, partially obscuring them from view.

Dozens of cars were damaged, some crumpled almost beyond recognition, others with their windows blown out or cracked by the blast. Several were completely gutted, only charred carcasses remaining.

Firefighters rushed to the area, attempting to control blazes started by the explosion, which one state broadcaster said took place near a school, adding that children were believed to be among the dead and wounded.

The footage showed bloodied dead bodies with limbs askew and flesh gouged out strewn on the streets, with bystanders draping clothes or cardboard boxes over them.

One group of men worked to retrieve a body from inside a badly damaged yellow taxi, tugging at the jammed doors of the vehicle. A veiled woman wept as she walked from the scene, passing a man holding a terrified, sobbing young girl.

"I was in the street with my colleague when the ground shook beneath our feet," 32-year-old Anana said, not far from Sabaa Bahrat square.

"People started to scream `explosion, explosion` and we saw a cloud of thick, black smoke emerge from the scene of the attack."

The force of the blast knocked down fencing along the pavement and blew over doors inside buildings near the scene. Whole window frames were knocked out by the explosion, which also set trees surrounding the site on fire.

The attack occurred near the Syrian central bank, and security forces and the army quickly moved into the area to prevent people from approaching the scene of the attack.

On March 21, a huge explosion ripped through a Damascus mosque killing at least 49 people, including a key pro-regime Sunni cleric. And a month earlier, on Feburary 21, at least 83 people were killed in a spate of bombings in the city.

Elsewhere, UN Secretary General Ban Ki-moon said Monday that a UN inspection team was in Cyprus and ready to deploy to Syria to probe the alleged use of chemical weapons in the conflict.

"I can announce today that an advance team is now in Cyprus, the final staging point" before the mission heads to Syria, Ban said in The Hague. "We are ready."

"The UN is now in the position to deploy in Syria -- in less than 24 hours all logistical arrangements will in place," Ban said after President Bashar al-Assad called on the UN to probe allegations rebels had used chemical weapons.

"All we are waiting for is the go-ahead of the Syrian government to determine if any chemical weapons have been deployed," he added.

"We are still in the process of discussing it with the Syrian government."

Syria`s conflict, now in its third year, is believed to have killed more than 70,000 people. On Sunday alone, 157 people were killed throughout the country, according to the Syrian Observatory for Human Rights watchdog.